DOI QR코드

DOI QR Code

A Study on Energy Saving Performance by Night Purge Cooling with Pressurized Under Floor Air Distribution System

가압식 바닥공조 시스템과 야간 외기냉방의 병용에 따른 에너지저감 성능에 관한 연구

  • Yoon, Seong-Hoon (Department of Architectural Engineering, Namseoul University)
  • 윤성훈 (남서울대학교 건축공학과)
  • Received : 2019.10.23
  • Accepted : 2020.02.14
  • Published : 2020.02.28

Abstract

It has been reported about the energy saving performance of UFAD(under floor air distribution) system and NPC(night purge cooling) system respectively which are applied for commercial buildings. However, when two systems are used at the same time, the effect of heat transfer from floor plenum to slab may vary depending on the operating conditions of NPC. In this study, cooling energy demands were analyzed for building models with UFAD and NPC by using TRNSYS 17 program. UFAD was applied as a cooling system of the base building model, and the cooling energy demands were compared for 64 cases in which the operating time, supply airflow rate, and outdoor air temperature(To) of NPC. As a result, it was confirmed that the cooling energy demands were reduced to 30 ~ 80% level compared to UFAD alone, and in particular, the energy demand was reduced in proportion to the supply airflow rate or the operating time while To was 16 ~ 20℃. However, when To was 22℃, the increase in the supply airflow rate or the operating time results in a disadvantage in terms of cooling energy demands. In addition, the cooling energy demands for UFAD+NPC model were analyzed by applying weather data from three regions with different average outdoor air temperatures. As a result, the cooling energy demand of operating NPC only when To was below 20℃ was reduced by 27% compared to that of operating NPC continuously for 8 hours.

Keywords

References

  1. Ali Alajmi, Wid El-Amer, Saving energy by using underfloor-air-distribution (UFAD) system in commercial buildings, Energy Conversion and Management Vol. 51, pp. 1637-1642, 2010. https://doi.org/10.1016/j.enconman.2009.12.040
  2. Yu, K. H., Yoon, S. H., Jung, H. K., Kim, K. H., and Song, K. D., Influence of lighting loads upon thermal comfort under CBAD and UFAD systems, Energies, Vol. 8, pp. 6079-6097, 2015. https://doi.org/10.3390/en8066079
  3. Underfloor Air Distribution (UFAD) Design Guide, Bauman, ASHRAE, 2003.
  4. Miura, K., Takemasa, Y., and Yoshida, H., Evaluation of thermal load reduction and effect to indoor environment by hybrid ventilation system, Journal of environmental engineering(Transaction of AIJ), Vol. 76 No. 660, pp. 159-168, 2011. https://doi.org/10.3130/aije.76.159
  5. Jung, J. H., Consideration of Appropriate Thermal Storage Time of Air-Conditioning System with Slab Thermal Storage in an Office Building by Use of Measurement Value, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 22, No. 10, pp. 719-726, 2010.
  6. Kim, S. Y., Won, J. K., Kim, J. H., and Song, D. S., Energy saving effect of the night purge control using ERV in a school building, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 28, No. 11, pp. 421-427, 2016. https://doi.org/10.6110/KJACR.2016.28.11.421
  7. Yoon, S. H., Jang, H. I., Kim, K. A., Yu, K. H., and Suh, S. J., An energy performance evaluation of UFAD system under the various conditions of thermal load, Korean journal of air-conditioning and refrigeration engineering, Vol. 25, No. 1, pp. 14-19, 2013. https://doi.org/10.6110/KJACR.2013.25.1.014